Improving the composition's from which medical articles, such as medical devices and coatings for medical devices, are produced is an ongoing goal of biomaterials research. An example of such a medical device is an implantable medical device.
A stent is an example of an implantable medical device that can benefit from improvements such as, for example, a coating that can be used as a vehicle for delivering pharmaceutically active agents in a predictable manner.
Stents play an important role in a variety of medical procedures such as, for example, percutaneous transluminal coronary angioplasty (PTCA). Stents act as a mechanical intervention to physically hold open and, if desired, expand a passageway within a subject. However, problems with the use of stents can include thrombosis and restenosis, which may develop several months after a particular procedure and create a need for additional angioplasty or a surgical by-pass operation.
To address these problems, stents are being developed to provide for the local delivery of agents, i.e., anti thrombotic and anti restenosis agents. One method of local delivery includes coating the surface of a medical article, e.g., a stent, with a polymeric carrier and attaching an agent to, or blending it with, the polymeric carrier. Agents can be used alone, and in combination. However, there is continual need for novel ways to control the release rate of an agent from a coating and for improving the mechanical properties of a stent coating.
The present invention provides such methods and is also directed to overcoming other deficiencies in the art.